The overall objective of the proposed research is to examine the possible regulation of glycolysis in brain by subcellular translocation of glycolytic enzymes. The partitioning of hexokinase, phosphoglucose isomerase, phosphofructokinase, as well as the non-glycolytic enzyme creatine kinase, between soluble and membrane-bound forms will be determined as a function of the energy status of synaptosomes and neurons. Isolated synaptosomes and neurons from rat brain will be used as a model of intact brain. Preliminay studies on neuroblastoma and glioma cell lines in tissue culture will also be initiated. The energy status of the isolated cells will be varied in a controlled manner and the subcellular distribution of the five enzymes correlated with the energy status as determined by the concentrations of ATP, ADP, AMP, creatine phosphate and glucose-6-phosphate.